Behavior of 137Cs in ponds in the vicinity of the Fukushima Dai-ichi nuclear power plant. (November 2017)

• Record Type: Journal Article
• Authors: Wakiyama, Yoshifumi; Konoplev, Alexei; Wada, Toshihiro; Takase, Tsugiko; Byrnes, Ian; Carradine, Matthew; Nanba, Kenji
• Is Part Of: Journal of environmental radioactivity. Volume 178/179(2017)
• Page Start: 367
• Page End: 376
• Publication Date: 2017-11
• Subjects: Dissolved 137Cs -- Distribution coefficient -- Fukushima -- Particulate 137Cs -- Pond; Radioactivity -- Periodicals; Radiation, Background -- Periodicals; Radioecology -- Periodicals; Radioactive pollution -- Periodicals; Environmental Pollutants -- Periodicals; Radioactive Pollutants -- Periodicals; Radioactivity -- Periodicals; Radioécologie -- Périodiques; Pollution radioactive -- Périodiques; Fond de rayonnement -- Périodiques; 539.752
• DOI: 10.1016/j.jenvrad.2017.07.017
• Languages: English
• ISSNs: 0265-931X

Abstract

Abstract: 137 Cs activity concentration in the water of four ponds, Suzuuchi (SU), Funasawa (FS), Inkyozaka (IZ), and Kashiramori (KM), that are within 10 km of the Fukushima Dai-ichi nuclear power plant were observed from April 2015 to August 2016. 137 Cs inventories in soils surrounding SU, FS, IZ, and KM were 6.4, 2.9, 2.1, and 0.9 MBq m −2, respectively. 137 Cs inventories in the bottom sediments of SU, FS, IZ, and KM were 13, 8.9, 1.6, and 1.1 MBq m −2, respectively. Higher 137 Cs inventories in bottom sediment than those of soil in SU and FS suggest that 137 Cs was delivered to and accumulated in these ponds. Mean total 137 Cs activity concentrations in SU, FS, IZ, and KM were 41, 13, 9.5, and 1.4 Bq L −1, respectively. Particulate 137 Cs concentration accounted for 71–90% of total 137 Cs in the water samples, on average. The mean distribution coefficient, K d, in SU, FS, IZ, and KM was 1.3 × 10 5, 2.1 × 10 5, 1.7 × 10 5, and 6.2 × 10 5 L kg −1, respectively. These K d values were higher than the K d values observed in the Chernobyl area by 1–2 orders of magnitude. Although no significant decreasing trends were found, dissolved 137 Cs activity concentration tended to be low during winter in all four ponds. Dissolved 137 Cs activity concentrations were proportional to K + and DOC concentrations in all the ponds. The results from principal component analysis performed for 137 Cs activity concentration and water chemistry data sets suggested that there were different mechanisms behind variability of dissolved 137 Cs activity concentrations for each pond. Continuous monitoring is required to reveal temporal trends in 137 Cs activity concentrations of these waters and controlling factors of such in closed water systems in Fukushima. Highlights: Total 137 Cs concentration in the pond water was up to 77 Bq L −1 . Dissolved 137 Cs activity concentrations during winter were low for all four ponds. Dissolved 137 Cs activity concentration was proportional to K + and DOC concentrations.